Printing press and method for operating a printing press

ABSTRACT

The invention relates to a printing press and a method for operating a printing press comprising at least one print unit, a drive unit that is assigned to the print unit, a control unit at least for regulating a drive unit, and a print mark measuring device, register measuring device, or register mark measuring devices. The print mark measuring device, or the register measuring device is directly connected to the control unit provided at least for regulating a drive unit by means of a signal transmission means. The print mark measuring device directly transmits a print mark signal to the control unit, the control unit calculating a correction factor for regulating the movement of at least one drive unit such that the printing quality is improved.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the US National Stage of International ApplicationNo. PCT/EP2004/003072, filed Mar. 23, 2004 and claims the benefitthereof. The International Application claims the benefits of Germanapplication No. 10318209.8, filed Apr. 22, 2003, both applications areincorporated by reference herein in their entirety.

FIELD OF INVENTION

The invention relates to a printing press or to a method for operating aprinting press, as well as to a control unit for regulating a drive unitof the printing press.

SUMMARY OF THE INVENTION

Application DE 197 23 059 A1 discloses a cylinder printing press as anexample of a printing press. With this type of cylinder printing pressregister controllers are used for accurate baseline alignment of a printcylinder pressing on a side of a track. Register deviations picked upare fed to an input of the register controller by a sensor which isassigned to one side of the track. Via a further input the registercontroller is connected to a bus of a higher-ranking controller. Thehigher-ranking controller comprises a control console, section computerand service interfaces accessible via modems. The required values forregulation of drive motors are provided by the higher-rankingcontroller. In application DE 197 23 059 A1 it is especially pointed outthat a color register does not move outside a tolerance area. The speedof the color register regulation is of particular importance. The fasterthe registration is regulated the more advantageous this is. In thesense of minimizing the error delay time it is proposed to arrange asensor immediately behind each print position.

From the cost consideration standpoint however it is pointed out that itis sufficient to provide just one sensor per track side and to placethis sensor as close as possible behind the last print position which isto be adjusted for correct baseline alignment to a reference color.

For register regulation register marks are printed for example by printcylinders on the track which are recorded by means of pair of sensorsarranged beyond the last print unit. The register marks printed on thetrack are picked up by sensors and evaluated in a measurement head ofthe sensor. The register discrepancies between the print cylinders and areference cylinder determined are fed from an output of the sensor to aninput of the register regulator.

Register marks are thus printed markings which are also known as printmarks and which can be employed for optimizing printing.

The object of the present invention is to achieve a low-cost or animproved faster processing of signals of a color register regulation,i.e. in general of a register regulation or a print mark which is pickedup by a sensor, a print mark scanner. A further object is to achieve animproved error correction.

This object is successfully achieved by the claims. The dependent claimsare advantageous, non-self-evident embodiments of the invention.

One embodiment of the printing press is for example an individual printunit. A further embodiment of the printing press is for example aprinting press with two or more print units. The print units areadvantageously harmonized with one another.

An inventive printing press features at least one print unit, a driveunit which is assigned to the print unit, a control unit for at leastregulating a drive unit and a print mark measuring device and/orregister measuring device. The print mark measuring device or theregister measuring device is directly connected by a means for signaltransmission to the control unit, which is at least provided forregulating a drive unit. The direct connection reduces the signal path,i.e. the signal delay time, by comparison with the patent applicationmentioned above. In this way it is possible to react more quickly andbetter to discrepancies in the print image.

The register measuring device for example features a CCD camera or ascanning device. Optical signals picked up by the register measuringdevice allow the baseline alignment of the printer to be determined. Forcolor printing this involves color registers also known as registrationmarks—or accordingly a color register measuring device. A color registermeasuring device can be used both for print marks and also for printingwithout print marks using the print itself.

The printing press for example features a large number of printingmechanisms which, to produce a good print image, have to rotate veryaccurately synchronously and correctly positioned in relation to oneanother. To check this print marks are made on the paper to be printedfor example. For evaluation of these print marks at least one print markmeasuring device—also know as a measuring scanner—is provided. With theaid of the print mark measuring device the difference between theindividual print mechanisms or colors is measured. This type ofdifference can also be determined by evaluating the print image with theaid of a (color) register measuring device and a correspondingevaluation unit. At this point and below a print mark is also to betaken, alternatively or in combination, to mean a registration mark. Theprint mark measuring device is then to be understood as a register markmeasuring device which is used as an alternative to or in combinationwith the print mark measuring device. The register mark measuring deviceis intended for detection of the register marks. For the use of theimproved print mark measuring device or register mark measuring device ahigh-resolution image analysis device is in this case especially ofadvantage. The measurement of the difference is used for determinationof at least one correction factor for a scope register of the printmechanisms or color lying outside the tolerance for example. Thesecorrection factors are time-critical and the precise control of thesecorrection factors is very important for the quality of the print image.The print mark measuring device or the register measuring device isconnected directly to a control unit for drive regulation of a drive ofthe printing press. A means for signal transmission such as transmissionover a cable or also radio transmission can be used for the connection.A direct connection of this type results in fast processing of thecorrection factor which is calculated in the control unit for example,and thus in an improvement in the print image quality as well.

By contrast, in application DE 197 23 059 A1 the signal of the sensor istransferred to an assigned register controller, with the registercontroller being connected by a bus to a higher-ranking control and acorrection factor for improving the baseline alignment being able to betransferred corrected via the control console to a drive controller as arequired value of the higher-ranking controller.

This long chain of communication partners is now shortened in accordancewith the invention by the print mark measuring device being connected bya means for signal transmission to the control unit, which is at leastintended for regulating one drive.

In an advantageous embodiment of the invention the print mark measuringdevice evaluates the measurement signal of the print mark measuringdevice or the register measuring device in an evaluation unit. Theevaluation unit of the print mark measuring device has a direct dataconnection for example via a serial connection to the control unit, thatis a drive control of the print mechanism. In the control unit softwarecan be executed which evaluates the measured values of the print markmeasuring device and calculates the correction factors or alsoimplements the correction directly.

Through the direct connection and thereby faster processing of thecorrection factors a qualitative improvement of the print image isproduced. Further a cost saving results from the omission of thepreviously required separate correction processor. The correction signalor the correction signals are for example sent via an existingcommunication connection within a printing press from the control unitto a control console.

The print mark measuring device which features an evaluation unit, withthe evaluation unit converting the signals generated by a print markmeasuring device into digital signals are example, sends these digitalsignals for example via a bus system to the control unit. A bus systemwhich is already employed in the printing press can advantageously beused as a means for signal transmission. The same procedure can be usedfor a register measuring device.

In a further advantageous embodiment the control unit features theintegrated evaluation unit which converts a signal generated by theprint mark measuring device or the register measuring device, e.g. ananalog signal, into a digital signal that can be processed by thecontrol unit.

In a further advantageous embodiment the control unit, which is at leastprovided for regulation one drive unit and is directly connected to theprint mark measuring device or the register measuring device, has amaster functionality in respect of further drive units or in respect offurther control units. A drive unit in this case features at least oneelectric motor and a power converter.

The desired object is also successfully achieved by a control unit forregulating a drive unit of a printing press, with the control unitfeaturing a signal interface for entry of a signal of a print markmeasuring device or a register measuring device.

In a method for operating a printing press the print mark measuringdevice transfers a print mark signal or the register measuring devicetransfers a register measuring signal to the control unit. A correctionfactor for regulating the movement of at least one drive unit iscalculated by the control unit.

Exemplary embodiments of the invention are shown in the drawing and areexplained in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a printing press,

FIG. 2 shows a further printing press,

FIG. 3 shows the communication between of a print mark measuring deviceand a drive unit with assigned control device, and

FIG. 4 shows the signal path of a print mark signal.

DETAILED DESCRIPTION OF INVENTION

In the drawing in FIG. 1 the layout of a printing press DM is shown inthe form of an overview diagram. From paper rollers P1 to P3 papertracks PB1 to PB23 pass through print units DE, DE1 and DE2 as well asto a folder unit F.

The paper track PB1, after passing through the print units DE1 and DE2,arrives at further processing units which are not however shown in thedrawing in accordance with FIG. 1. The paper track PB1 thus leaves thesystem in the drawings where indicated by the dashed line.

The print units DE, DE1 and DE2 are shown in the drawing by anapproximately H-shaped exterior contour. In the print units DE, DE1 andDE2 There are 10 of cylinders ZY in each case arranged into two groupsG1, G2 of five cylinders ZY each. Cylinders ZY are here taken to meanall cylinders or wheel-shaped machine elements of a print unit DE, DE1DE2 as well as of a folder unit F. The paper tracks PB1 to PB3 run overthese groups G1, G2 which are known as print locations in the printunits DE.

A print location consists essentially for example of a rubber cylinder,a plate cylinder and a color or damping mechanism. With each printlocation a color can be printed on a page. All print locations whichoperate on a folder unit F, i.e. for which the printed paper tracks PB1to PB3 are fed to a folder unit F belong to one rotation. In this casethe print units DE, DE1, DE2 are usually accommodated in print turrets.

A drive unit A1 to A29 belongs to each individual driven cylinder. Thedrive unit A1 to A29 is assigned a control unit RE1 to RE29. Dependingon the degree of integration for the drive units a drive unit typicallycontains a motor and a power converter. In a higher level of integrationthe drive unit features an integrated control unit RE1 to RE29. Driveunits A30 to A34 or associated control units RE30 to RE34 are alsoprovided for the folder unit F. The print units DE, DE1 and DE2 or thefolder unit F feature for each drive group which features the driveunits, one control unit RE1, RE20, RE21 and RE30 with masterfunctionality. The control units RE1 to RE10 of a drive group arenetworked with each other by data connections. The control units RE1,RE20, RE21 and RE33 or the drive units A1, A20, A21 and A30, which havea control or master functionality, are identified in the drawings by abolder outline around the unit.

A group of drive units or control units is assigned to an associatedcontrol computer L1 to L4 and have data connections to this computer.The control computers L1 to L4 are also interconnected by controlcomputer communication LK1 to LK3. This is shown in the drawing by adotted line. Here too further embodiments of the data networking ispossible.

A control computer L1 to L4 takes over a higher-ranking processorganization. At the end of the print units DE and DE2 a print markmeasuring device ME1, ME2 and ME3 is arranged, which is used to pick upprint marks of the paper tracks PB1, PB2 and PB23. The print markmeasuring device ME1, ME2 and ME3 is connected to a control unit RE1 orRE21. The control unit RE1 or RE21 determines the correction factor forthe drive unit or the drive units to improve the print image. This getsaround the procedure that was previously needed where the correctionfactor was calculated by a separate evaluation electronics and outputfor example by a pulse-width modulated binary signal to the relevantdrive units of the print mechanisms. A long path which was previouslyrequired as regards the transmission of the correction factors to acontrol computer of the printing press e.g. via a serial connection, byProfibus® or Arcnet, is no longer necessary.

By linking the print mark measuring device ME1, ME2, ME3, e.g. by aserial data connection (DS) directly to the control unit RE1, RE21 orthe drive controller of the print mechanism, the signal path issignificantly shortened which benefits faster evaluation of the signalsor correction. Direct linkage and thereby fast processing of thesecorrection factors produces an improvement in print image quality. Theomission of a separate correction computer also produces costoptimization. The correction signals are transmitted via existingcommunication connections of the control units to a control computer orto a control console.

For the paper track PB1 a register measuring device RME is provided asan alternative to or in combination with the print mark measuring deviceME1, said device having a data connection to the control unit RE1. Aregister measuring signal RMS, shown in FIG. 1 as an arrow is then usedfor correction of the print.

The diagram in FIG. 2 shows a printing press DM in which print tracks DBrun which can be folded in a folder unit F. The print mark measuringdevice ME5 serves as a sensor for the print marks on the print tracksand transmits the sensor data to an integrated evaluation unit of thecontrol unit RE. The control units RE are linked to various drive unitsA of a print unit DE1, DE2, DE3 and DE4.

The print mark measuring device ME4 features an evaluation unit AE, withthe print mark signal able to be transmitted to the control unit RE viaa bus connection The control units RE have data connections to thecontrol computers LST1, LST2 and LST3. The control consoles LST1, LST2and LST3 have data connections to a control unit LE.

The diagram in FIG. 3 shows the data connections between a print markmeasuring device ME and a drive unit A, to which a control unit RE isassigned. The control unit has an interface SNR and the print markmeasuring device an interface SNM. The connection is made by means of abus cable BK. Depending on the degree of integration the control unit isintegrated into the drive unit for example, so that in the drive unitcontrols such as current regulation and other controls such as torqueregulation or speed regulation are undertaken.

The diagram in FIG. 4 shows the signal path of a print mark signal DMS.A print mark signal DMS is generated by the print mark measuring deviceME and is transmitted to a control unit RE. In the control unit acorrection factor calculation MB is undertaken which outputs acorrection factor KW. This correction factor KW serves as input signalfor a drive control AR, with the drive control AR having further inputsignals available to it. The corrected output signal AS is then used formore precise regulating of the drives, so that an improvement in printquality can be achieved. The correction factor KW can additionally beoutput to a control console LS.

1.-10. (canceled)
 11. A printing press, comprising: a print unit; adrive unit assigned to the print unit; a control unit for regulating thedrive unit; and a print mark measuring device and/or register markmeasuring device and/or a register measuring device, wherein the printmark measuring device and/or the register mark measuring device and/orthe register measuring device are directly connected to the controlunit.
 12. The printing press in accordance with claim 11, wherein theprint mark measuring device and/or the register mark measuring deviceand/or the register measuring device are connected by a means for signaltransmission to the control unit.
 13. The printing press in accordancewith claim 11, wherein the print mark measuring device and/or theregister mark measuring device and/or the register measuring devicecomprises an evaluation unit.
 14. The printing press in accordance withclaim 11, wherein the control unit comprises an integrated evaluationunit.
 15. The printing press in accordance with claim 11, wherein acorrection factor can be calculated by the control unit to regulate themovement of the drive unit.
 16. The printing press in accordance withclaim 13, wherein a correction factor can be calculated by the controlunit to regulate the movement of the drive unit.
 17. The printing pressin accordance with claim 14, wherein a correction factor can becalculated by the control unit to regulate the movement of the driveunit.
 18. The printing press in accordance with claim 11, wherein theprint mark measuring device and/or the register mark measuring deviceand/or the register measuring device are connected to the control unitby a field bus system or a serial link.
 19. The printing press inaccordance with claim 13, wherein the print mark measuring device and/orthe register mark measuring device and/or the register measuring deviceare connected to the control unit by a field bus system or a seriallink.
 20. The printing press in accordance with claim 14, wherein theprint mark measuring device and/or the register mark measuring deviceand/or the register measuring device are connected to the control unitby a field bus system or a serial link.
 21. The printing press inaccordance with claim 15, wherein the print mark measuring device and/orthe register mark measuring device and/or the register measuring deviceare connected to the control unit by a field bus system or a seriallink.
 22. The printing press in accordance with claim 12, wherein afield bus system or a serial link is provided as means for signaltransmission.
 23. The printing press in accordance with claim 11,wherein the control unit has a master functionality with regard tofurther drive units or with regard to further control units.
 24. Theprinting press in accordance with claim 13, wherein the control unit hasa master functionality with regard to further drive units or with regardto further control units.
 25. The printing press in accordance withclaim 14, wherein the control unit has a master functionality withregard to further drive units or with regard to further control units.26. The printing press in accordance with claim 15, wherein the controlunit has a master functionality with regard to further drive units orwith regard to further control units.
 27. A control unit for regulatinga drive unit of a printing press in accordance with claim 11, whereinthe control unit comprises a signal interface for input of a signal of aprint mark measuring device and/or a register mark measuring deviceand/or of a register measuring device.
 28. The control unit inaccordance with claim 27, wherein the control unit is provided fordetermining a correction, factor from the signal of the print markmeasuring device and/or register mark measuring device or the signal ofa register measuring device for regulating the movement of at least onedrive unit.
 29. A method for operation of a printing press, the printingpress comprising: a print unit; a drive unit assigned to the print unit;a control unit for regulating the drive unit; and a print mark measuringdevice and/or register mark measuring device and/or a register measuringdevice, wherein the print mark measuring device and/or the register markmeasuring device and/or the register measuring device are directlyconnected to the control unit, the method comprising: transmitting aprint mark signal and/or the register mark signal from the print markmeasuring device and/or the register mark measuring device to thecontrol unit, or transmitting a register measuring signal from theregister measuring device to the control unit.
 30. The method inaccordance with claim 29, wherein a correction factor for regulating themovement of at least one drive unit is calculated by the control unitfrom the print mark signal or from the register mark signal or from theregister measuring signal.